<?
   $forum_time = time();
   echo "<br>Begin = ";
   echo mktime(0,0,0,02,13,2009);
   echo "<br>End = ";
   echo mktime(0,0,0,02,14,2009);
   echo "<br>";
   $time_begin = 1233871200;
   $time_end = 1233957600;
   $forum_time = 1233957602;

   if ($forum_time >= $time_begin && $forum_time <= $time_end)
     echo "yes";
?>